www.floridasolardesigngroup.com / they made a mistake and haven't solved it yet

We signed the contract with the company www.floridasolardesigngroup.com. They agreed to install solar electricity panels within couple of weeks. But they told us that it would cost the larger sum. We paid the deposit and they started to work, but they made only half of the work and told us that they have made a mistake. They scared us. We waited 2 more weeks, but they still haven’t solved the problem.
USA, 6418 Commerce Park Dr
Fort Myers, FL 33966